The present invention relates to a control device for controlling a vehicle drive apparatus which includes a fluid coupling having a direct-coupling clutch and a transmission, and outputs rotation of an input member drive-coupled to an engine and a rotary electrical machine to an output member.
In recent years, hybrid vehicles capable of improving fuel efficiency of an engine and reducing exhaust gas by using an engine and a rotary electrical machine in combination as driving force sources have been brought into practical use. As an example of a vehicle drive apparatus used in such a hybrid vehicle, Japanese Patent Application Publication No. 2003-278910 listed below describes a vehicle drive apparatus which includes a fluid coupling having a direct-coupling clutch and a transmission and outputs rotation of an input member, which is drive-coupled to an engine and a rotary electrical machine, to an output member via the fluid coupling and the transmission.
In this vehicle drive apparatus described in Japanese Patent Application Publication No. 2003-278910, when the accelerator opening is fully closed by the intention of the vehicle driver, a control device controls the direct-coupling clutch to engage regardless of whether the direct-coupling clutch is in an engaged state or released state. However, when the rotation speed of the engine drops due to full closing of the accelerator opening, and a large difference in rotation speed occurs between an input side rotation member and an output side rotation member of the fluid coupling, shock (engagement shock) may be generated in the vehicle when the direct-coupling clutch is engaged in this state, which is unfavorable. Accordingly, in the vehicle drive apparatus, when the direct-coupling clutch is changed from a released state to an engaged state, the rotation speed of the rotary electrical machine is controlled to synchronize the rotation speed of the input side rotation member of the fluid coupling to which the rotary electrical machine is drive-coupled with the rotation speed of the output side rotation member of the fluid coupling to which the transmission is drive-coupled, and then the direct-coupling clutch is engaged. This suppresses generation of shock by engaging the direct-coupling clutch in the vehicle.